Homomorphic key derivation

Abstract

A processor of a remote crypto cluster (RCC) may obtain an encrypted specific key from at least one data source through at least one network. The processor of the RCC may derive intermediate data in blind based on the encrypted specific key. The intermediate data may include information from which a derived key is derived. The processor of the RCC may send the intermediate data in blind to a client device.

What is claimed is: 
     
       1. A key derivation method comprising:
 obtaining, by a processor of a remote crypto cluster (RCC), a client generated public key of a key pair and a Hashed Message Authentication Code (HMAC)-based key derivation function (HKDF) from a client device through at least one network; 
 obtaining, by the processor of the RCC, an encrypted specific key and a blinded project key from at least one data source through the at least one network, the at least one data source including a virtual key manager (VKM) including a processor that sends the encrypted specific key to the RCC through the at least one network and a project key server (PKS) including a processor that sends the blinded project key to the RCC through the at least one network; 
 deriving, by the processor of the RCC, intermediate data in blind based on the public key, the HMAC-based HKDF, the encrypted specific key, and the blinded project key, the intermediate data including information from which a derived key is derived; and 
 sending, by the processor of the RCC, the intermediate data in blind to the client device through the at least one network. 
 
     
     
       2. The method of  claim 1 , further comprising sending, by a processor of the at least one data source, a blinding value to the client device, wherein the processor of the RCC is restricted from obtaining the blinding value. 
     
     
       3. The method of  claim 2 , further comprising deriving, by a processor of the client device, the intermediate data in clear based on the blinding value. 
     
     
       4. The method of  claim 3 , further comprising obtaining, by the processor of the client device, the derived key from the intermediate data in clear. 
     
     
       5. The method of  claim 4 , wherein the obtaining of the derived key is performed using a key derivation function. 
     
     
       6. The method of  claim 1 , further comprising:
 generating, by a processor of the client device, public key data; and 
 sending, by the processor of the client device, the public key data to the processor of the RCC through the at least one network to request the intermediate data. 
 
     
     
       7. A key derivation system comprising:
 at least one data source including a virtual key manager (VKM) including a transceiver and a processor and a project key server (PKS) including a transceiver and a processor; and 
 a remote crypto cluster (RCC) including a transceiver and a processor configured to:
 obtain a client generated public key of a key pair and a Hashed Message Authentication Code (HMAC)-based key derivation function (HKDF) from a client device through at least one network by the transceiver of the RCC, wherein the processor of the VKM is configured to send the encrypted specific key to the RCC through the at least one network by the transceiver of the VKM and the processor of the PKS is configured to send the blinded project key to the RCC through the at least one network by the transceiver of the PKS; 
 obtain an encrypted specific key and a blinded project key from the at least one data source through the at least one network by the transceiver of the RCC; 
 derive intermediate data in blind based on the public key, the HMAC-based HKDF, the encrypted specific key, and the blinded project key, the intermediate data including information from which a derived key is derived; and 
 send the intermediate data in blind to the client device by the transceiver of the RCC. 
 
 
     
     
       8. The system of  claim 7 , further comprising the at least one data source including a transceiver and a processor, wherein:
 the processor of the at least one data source is configured to send a blinding value to the client device by the transceiver of the at least one data source; and 
 the processor of the RCC is restricted from obtaining the blinding value. 
 
     
     
       9. The system of  claim 8 , further comprising the client device including a processor configured to derive the intermediate data in clear based on the blinding value. 
     
     
       10. The system of  claim 9 , wherein the processor of the client device is configured to obtain the derived key from the intermediate data in clear. 
     
     
       11. The system of  claim 10 , wherein the obtaining of the derived key is performed using a key derivation function. 
     
     
       12. The system of  claim 7 , further comprising the client device including a transceiver and a processor configured to:
 generate public key data; and 
 send the public key data to the processor of the RCC through the at least one network by the transceiver of the client device to request the intermediate data.